Probiotics and Weight Control: How Gut Bacteria May Impact Your Weight

Probiotics and Weight Control: How Gut Bacteria May Impact Your Weight

Your intestines are teaming with bacteria – some are “good bacteria” that enhance immunity and help protect you against illness. These gut-friendly bacteria help to keep more sinister bacteria in check by competing for the same resources. We already know gut bacteria impact the health of your immune system. Not convinced? Surprisingly, 80% of your immune system lies in your digestive tract. What’s also becoming obvious is how bacteria impact other functions including body weight. Is it possible that changing these bacteria by taking probiotics could enhance fat loss?

Gut Bacteria and Weight Loss

A recent study carried out by scientists at Harvard found that mice that underwent gastric bypass surgery for weight loss experienced marked changes in the type of gut bacteria in their intestines. In fact, some experts believe one of the ways gastric bypass surgery helps with weight loss is by altering the composition of gut bacteria. What’s even more interesting is when the bacteria from mice that have undergone bypass surgery are transferred to other mice, they lost weight too! Can changing your gut bacteria make it easier to lose weight?

 Probiotics and Weight

Of course, you can’t transfer bacteria from one human to another at this point as you can in mice, but taking a probiotic supplement or eating foods like yogurt and other fermented foods and beverages that have natural probiotics is a way to alter the type of gut bacteria that live in your intestines.

Interestingly, some research shows that people who are overweight or obese tend to have more of a certain type of intestinal bacteria. These bacteria seem to make nutrient and calorie extraction from certain foods more efficient. This leads to more calories absorbed from foods and subsequent weight gain. The question is whether getting rid of this particular bacteria called methanobrevibacter smithii makes it easier to lose weight.

Can Probiotics Help You Shed Belly Fat?

One factor that contributes to increased belly fat is higher levels of cortisol. Cortisol is a hormone released in response to stress by the adrenal cortex, a gland located just above your kidney. It’s a major contributor to insulin resistance and increased belly fat. One study showed that human volunteers who took a probiotic supplement had lower cortisol levels than those that took a placebo. Another study published in the European Journal of Clinical Nutrition showed that subjects that took a probiotic supplement containing the bacteria Lactobacillus Gasseri for three months lost belly fat and reduced the circumference of their waist.

 Probiotics and Weight Control: How Probiotics Could Make It Easier to Lose Weight

As discussed above, one possible way probiotics may help with weight control is by lowering cortisol level and reducing insulin resistance, thereby decreasing your body’s tendency to store fat, especially fat around the belly. Probiotic bacteria may also have a more local effect on the intestines by altering the absorption of certain nutrients and how many calories you absorb with a meal. Plus, probiotics have a beneficial effect on your immune system. This could help you fight off some types of viruses and bacteria that cause infection, especially intestinal infections.

How to Get Probiotics

There are so many types of probiotic bacteria and not all of them necessarily have the same benefits. When you take a probiotic supplement, you may not get the bacteria that help control belly fat. More research will be needed to see which bacteria have this effect and which don’t. At that point, a probiotic supplement might be formulated that had appropriate amounts of belly fat blasting bacteria. Until then, it’s best to get probiotics naturally by eating more fermented foods and yogurt with active cultures.

Miso, tempeh, kefir, and kimchee are other natural sources of probiotic bacteria. Enjoy these foods in abundance knowing you’re keeping your digestive tract healthy – and, possibly, making it easier to shed fat, especially belly fat.



Medical News Today. “Changes to Gut Microbiota May Play a Role in Weight Loss”

British Journal of Nutrition. 105, 755-764. (2011)

European Journal of Clinical Nutrition. 64: 636-643. (2011)

Eur J Clin Nutr. Jun;64(6):636-43. (2010)


Related Articles By Cathe:

Probiotics: Can Friendly Bacteria Help You Lose Weight?

4 Science-Backed Reasons to Add More Fermented Vegetables to Your Diet

The Problem with Probiotic Supplements: Are They What They Seem to Be?


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